The use of circuit members, e.g., electronic modules, which include one or more semiconductor chips as part thereof for being electrically coupled to other circuit members referred to in the art as printed circuit boards or ceramic substrates is becoming more and more popular in the electronics packaging field. For increased wiring and input/output (I/O) densities, the use of such members wherein solder elements form the connecting medium is especially becoming more widespread. Various examples include what are referred to as ball grid array packages such as tape ball grid arrays (TBGAs), ceramic ball grid arrays (CBGAs) and plastic ball grid arrays (PBGAs), all of which include some form of substantially planar substrate on which one or more chips are coupled. These assemblies, also referred to in the art as first level packaging structures, are then coupled to another circuit member such as a printed circuit board to form what is defined in the art as a second level packaging structure. Such assemblies are then incorporated into larger processing structures for performing information handling functions.
The use of various connector apparatus for coupling different circuit members is known in the art, with examples shown and described in U.S. Pat. Nos. 4,063,791 (Cutchaw), 4,390,220 (Benasutti), 4,420,203 (Awg et al), 4,683,423 (Morton), 4,874,318 (Spencer), 4,923,404 (Redmond et al), 4,933,808 (Horton et al), 5,215,472 (DelPrete et al), 5,397,245 (Roebuck et al) and 5,468,157 (Roebuck et al). In U.S. Pat. No. 4,063,791, e.g., chip-containing integrated circuit package is demountably positioned on a circuit (called a backpanel in U.S. Pat. No. 4,063,791) using a dielectric housing component which includes pins for coupling directly to the board's conductor elements. A cover is also utilized to cover the contained package. A somewhat similar structure is described in U.S. Pat. No. 4,390,220 wherein a hold-down lid securedly retains an integrated circuit package in position relative to a housing also mountable on a printed circuit board.
Connector devices for directly coupling a semiconductor chip to a circuit member such as a printed circuit board or the like are shown and described in U.S. Pat. Nos. 4,874,318, 4,683,423 and 5,468,157. In U.S. Pat. No. 4,874,318, a chip is mounted onto a circuit board using a lock nut cemented to the chip carrier and extending through a socket moulding aperture. The use of such a lock nut obviously presents a somewhat awkward structure which in turn necessitates the use of the interim socket structure, thereby adding costs to the assembly. In 4,683,423, a chip is electrically coupled to spring biased contact members located within a housing, such that this subassembly can then be positioned on and coupled to another circuit member. A rotational clamp is used to compress the chip onto the contact members. The requirement for utilization of several springs, strategically oriented within a housing, adds to the cost and complexity of this assembly. In U.S. Pat. No. 5,468,157, an interconnection system is described in which a semiconductor chip is electrically coupled to a "thin film interconnect" within a modular structure which also uses a threaded screw for exerting pressure onto the chip. A series of annular springs and associated plurality of shims are used as part of this connection scheme, thus adding to the cost and complexity of this design.
In accordance with the teachings of the present invention, there is provided a new and unique electrical assembly (and an actuating mechanism for use as part thereof) in which two circuit members are electrically coupled together and in which a minimum of elements are used while assuring a relatively low profile (desired for microelectronic packaging structures, including some of those mentioned above), and, significantly, while accommodating for non-planarity of the surfaces of one or more of the structure's components (e.g., the circuit board and/or chip). This latter feature is considered particularly critical when coupling extremely small, highly dense components such a semiconductor chips and the circuit members associated therewith. The invention as defined herein also provides relatively easy and simple disconnection of the electrical circuit members should this feature be desired. As understood from the following, the invention is able to provide all of these and other advantageous features discernible from the teachings hereinbelow with a minimum of components which comprise a relatively simple and inexpensive structure.
It is believed that an electrical assembly possessing the above features would represent a significant advancement in the art.